I set an alias for find -type f -print0 | xargs -0 -n 10 grep -i searchstring. Alias is: "mysearch". I search it like this: mysearch searchstring. How will I set your command to an alias? because, in your command searchstring is inside the command, not in the end.
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alwbtcJun 20 '12 at 9:54

If the error messages come from find (e.g. because there's a directory you can't traverse, redirect its errors to /dev/null.

find -type f -print0 2>/dev/null | …

If the error messages come from grep (e.g. because some files are unreadable), redirect its errors to /dev/null, or pass the -s option to tell it to ignore unreadable files.

xargs -0 grep -s -i searchstring /dev/null

There's no point in limiting the number of files passed together to grep. But you should add /dev/null so that grep always sees at least two files, otherwise grep omits the file name in its output if it has only one file argument. With GNU grep or Busybox (i.e. Linux or Cygwin), you can use the -H option instead.